SPI... Ethernet shield... power?

Hardware Nano Family Classic Nano
1

I've been playing with Nanos (and Micros, and Unos and ESP32s and even a Mega originally) for a while, but I only do simplistic playing around projects. I'm trying to get 'serious' about a project that will use Ethernet. I confess here at the beginning of this post - I am using a lot of 'clone' parts, and accept that they can be subject to trouble. Now... on to the problem.

I have a Hiletgo clone ENC28J60 clone board (I'll call refer to it as a 'shield' - but it has a 10-pin header on the top side and does not 'plug into' any Arduino format board) and a Nano clone (USB-C connector) that I'm trying to interface Using SPI. I am using test code from the Ethercard.h library - specifically the 'pings.ino' sketch. The code compiles and downloads to the Nano, but the instant I plug in the power to the Ethernet shield, 'D1' (LED) illuminates on the shield and I lose my serial connection. My pin wiring is:
Arduino Ethernet
D10 CS
D11 SI
D12 SO
D13 SCK
3.3V VCC (this is the pin I have been plugging/unplugging)
GND GND

My first thought was that perhaps the USB port on my laptop could not provide enough power to power both the Nano and the Ethernet card, so I 'inserted' a separate, powered USB hub between the laptop USB and the Arduino... that did not change anything. I added a line from the Arduino RST pin to the Ethernet RESET pin but that didn't change anything either. Having the RJ45 plugged into the shield or not also did not change anything.

I have 3 unused pins on the Ethernet card header
WOL (Wake on Lan?)
INT
CLKOUT

Anyone have any suggestions of where to start looking? I uploading the code and then powering the circuit(s) from a USB power adapter - but I need the serial port to know if the code is working.

Thanks in advance!
Arden

2

Are you using the EthernetENC library? The ethernet card should not draw much and should run ok with the Nano power source. This link may help: Mega 2560 china clone compatibility with ENC28J60 - #3 by devilution

3

I'm using the Ethercard.h library.

I just grabbed my little hand-held scope and it indicates that the 3.3V is dropping to 1.8V when I pull power to the Ethernet card/shield. I just started 'pondering' how I could power the Ethernet card separately and not pull the power from the Nano.

Arden

4

That was it... I used a couple diodes in series off of the 5V line and that did the trick. The 'pings.ino' sketch is now working. I'm going to have to 'up my game' here to include split power supplies to use this shield.

Thanks for listening!
Arden

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5

In future I suspect that we need more detail; e.g. a link to the "shield" that you're using.

Further be aware that the Nano is a 5V device so its output signals are 5V. If the "shield" is a 3.3V device, the 5V output signals of the Nano can damage the "shield".

6

enc28j60 is 5 V tolerant

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